GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2009 🢒 Lucerne 🢒 Engine 🢒 Engine Exhaust 🢒 Oxidation Catalytic Converter Replacement

Removal Procedure
  1. Raise and support the vehicle. Refer to.

    2. Object Number: 2146475 Size: SH
  2. Measure 36 mm (1.4 in) rear ward of the oxidation catalytic converter weld (1) and mark the converter outlet pipe at the cut point (2).
  3. Cut the converter outlet pipe at the marked cut point (2).

    4. Object Number: 2146476 Size: SH
  4. Remove the oxidation catalytic converter to muffler assembly nuts (1).

    5. Note: Gently move the muffler assembly rearward to obtain clearance.

  5. Remove the oxidation catalytic converter (2) from the vehicle. Discard the gasket.

Installation Procedure

    Object Number: 2146477 Size: SH
  1. Slide 2 service clamps (2) over the oxidation catalytic converter outlet pipe. Do not tighten at this time.

    2. Note: 

       • Always install a NEW gasket between the two catalytic converters.
       • It may be necessary to piratically lower the exhaust system in order to attach the catalytic converter to the muffler assembly.

  2. Position the oxidation catalytic converter (3) to the muffler assembly and the three way catalytic converter.
  3. Install the oxidation catalytic converter nuts (1) and tighten to 47 N·m (35 lb ft).

    4. Note: The clamps must be positioned midway on the catalytic converter output pipe with the ends pointing in the opposite directions as close together as possible.

  4. Verify the alignment of the oxidation catalytic converter (3) to the muffler assembly and tighten the clamps (2) to 54 N·m (40 lb ft).
  5. Lower the vehicle.
  6. Verify there are no exhaust leaks.